1. Field of the Invention
The present invention relates to an electric rotating machine having a drain member installed on a casing thereof.
2. Description of Related Art
It is known to provide a starter motor with a water drain device as described, for example, in Japanese Utility Model application Laid-open No. 4-137460. This water drain device includes a rubber drain pipe installed on the machine case (end frame, for example) of the starter motor. The drain pipe includes a fitting section to be inserted into a round hole formed in the end frame, and a drain tube section which is integral with the fitting section. A drain passage runs from the fitting section to the drain tube section.
This drain device has a problem in that, in addition to fabricating work of the end frame itself, drilling work is needed for making the round hole in the end frame. Moreover, it becomes necessary to remove burrs around the round hole after the drilling work.
In addition, since the diameter of a head portion of the fitting section of the drain pipe, which is to be located inside the end frame, is larger than that of the round hole formed in the end frame, the fitting section has to be deformed so that it can pass through the round hole and enter inside the end frame at the time of installing the drain pipe. This results in lowering the installation workability of the drain pipe, and lengthening the installation time of the drain pipe.
It may occur that the installability of the drain pipe can be improved by reducing the interference between the fitting section of the drain pipe and the round hole of the end frame by increasing the inner diameter of the round hole. However, in this case, there arises a fear that the drain pipe can easily come off the end frame when an external force is applied.